TNK2 gene amplification is a novel predictor of a poor prognosis in patients with gastric cancer

Backgrounds and Objectives We previously examined the amplification status of 10 kinase genes (PIK3CA, EPHB3, TNK2, PTK7, EGFR, MET, ERBB2, HCK, SRC, and AURKA) in gastric cancer (GC). This study aimed to determine the prognostic significance of these gene amplifications in GC. Methods A survival analysis was performed for GC patients. Since TNK2 amplification was identified as a prognostic marker in the analysis, we also examined the functional effect of TNK2 overexpression on gastric cells. Results A Kaplan–Meier analysis showed that the prognosis of patients with GC exhibiting TNK2 or AURKA amplification was significantly poorer than the prognosis of patients with GC without TNK2 or AURKA amplification. A further multivariate analysis revealed that TNK2 amplification was an independent predictor of a poor survival outcome among patients with GC (hazard ratio, 3.668; 95% confidence interval, 1.513–7.968; P = 0.0056). TNK2-overexpressing GC cells showed an increase in cell migration and non-anchored cell growth. Finally, microarray and pathway analyses revealed the aberrant regulation of some cancer-related pathways in TNK2-overexpressing GC cells. Conclusions These results suggested that TNK2 amplification is an independent predictor of a poor prognosis in patients with GC and leads to an increase in the malignant potential of GC cells. J. Surg. Oncol. 2014 109:189–197. © 2013 Wiley Periodicals, Inc.